Blast Protection Structures

ABSTRACT

A structure for example a blast protection structure ( 1 ) is provided formed by the inflation of one or more containers ( 2, 3, 4 ) and ( 5 ) which are then filled with a settable cement or other material to provide a rigid free-standing structure. Roof members ( 8, 9, 10, 11  and  12 ) ( FIGS. 2 and 3 ) may be provided also. The roof is formed by inflating roof supports ( 8, 9 ) and ( 10 ), forming a further roof member ( 11 ) from settable cement material above the roof supports ( 8, 9 ) and ( 10 ), deflating the roof supports ( 8, 9 ) and ( 10 ) when the further roof member ( 11 ) has set to leave the further roof member ( 11 ) in place and forming a structural roof member ( 12 ) above the roof member ( 11 ). The containers and/or inflatable supports may be formed from dropstitch material which provides internal reinforcing. The invention allows free-standing rigid structures to be produced without the need for conventional formwork. Thus, inflating equipment and means for pouring cement etc into the containers and supports is the only equipment required for the erection procedure.

This invention relates to structures, in particular blast protectionstructures of the type which may be rapidly deployed in battlefieldconditions or to counter-terrorist threats by e.g. suicide bombers.

In GB 2374625, the disclosure of which is incorporated herein byreference, a blast protection structure is described using inflatablebags having internal reinforcement such as by the use of “drop stitch”material, which effectively prevents or inhibits the side walls of thebags from bulging outwardly to any great degree, thereby maintaining thegeneral overall shape of the bags when filled with a blast suppressantsuch as water. While such structures are extremely effective inproviding speedy initial protection at or around a given location itwill be understood that they are necessarily temporary in nature ande.g. a knife or bullets may be used to rupture the bags, to thereafterrender them useless. On the other hand, providing a more permanent blastsuppression structure usually involves the use of construction workersto erect e.g. a concrete reinforced structure using rigid shuttering toform wall and roof sections and associated lifting apparatus for same.

The present invention is derived from the realisation that there is aneed to be able to quickly erect permanent protective structures in e.g.battlefield conditions or at vulnerable locations without specialistpersonnel or equipment.

According to a first aspect of the invention there is provided a methodof erecting a structure including the steps of: filling or partiallyfilling at least one container having internal reinforcement with asettable material which is thereafter allowed to set to form afree-standing rigid structure.

Preferably the method further includes the steps of forming at least twospaced apart rigid structures, to form at least two wall members andthereafter providing a fluid-fillable roof member spanning the at leasttwo wall members, the roof member having internal reinforcement, andthereafter forming a second roof member from the settable material andfollowing setting of the second roof member, deflating the first roofmember such that the second roof member then becomes a structural roofmember spanning the at least two wall members.

Preferably the method further includes the steps of forming a third roofmember over the said structural roof member after the first roof memberhas been deflated, to thereby provide increased structural strength.

The third roof member may be formed by filling at least one furthercontainer with a settable material which is thereafter allowed to set.Anchor points may be provided between the second, structural, roofmember and/or third roof members and each wall member.

At least one of the said wall members may be anchored to an existingstructure.

The inside of at least one container may be filled or partially filledwith the settable material and includes further reinforcement in theform of one or more rods.

The said at least one container may be filled sequentially such that atleast one settable material filling is allowed to set before another isintroduced.

The or each container may be used as formwork so that the method can beperformed employing only inflating equipment and/or means for pouringthe settable material and without separate rigid formwork or liftingequipment

The invention extends also to a method of producing a structure havingone or more inflatable containers each having internal reinforcement,including the steps of inflating the or each container with a fluid,whereafter the lowermost one or portion thereof is filled with asettable or pourable material which is then allowed to set or settle,whereafter the next successive layer is formed, supported by the firstsuch layer and also by the internal reinforcement.

The internal reinforcement may be in the form of dropstitch material.

The settable or pourable material may be: a settable cement or gypsumbased material; a particulate material such as sand or aggregate whichmay settle to form to a substantially rigid mass; or a settable foamand/or polymeric material.

The invention extends to an inflatable support member adapted to, inuse, bridge the gap between adjacent underlying support members and topermit a second support member to be formed and set thereon, such as aconcrete lintel, the inflatable support member being adapted to besubsequently deflated to allow the second, set, support member tothereafter bridge the gap between the two adjacent underlying supportmembers.

The member may be made of dropstitch fabric to provide internalreinforcement.

Further reinforcement may be provided in the form of reinforcing rods.

The further internal reinforcement may be provided for the or eachcontainer or support either integrally with the or eachcontainer/support prior to the or each container/support being filled,or by the or each container/support being adapted to be externallyaccessible for allowing the introduction of the further reinforcementfollowing filling and prior to any material setting in or on thecontainer/support.

The invention extends to inflatable formwork fillable with a settable orpourable material and shaped to form a rigid structural member, when thematerial of which the rigid structural member is to be formed sets, theformwork having internal reinforcement, and to a set of inflatableformwork for forming individual structural members for subsequentassembly into a structure.

The internal reinforcement may be drop stitch material.

The invention extends to a blast protection structure formed from atleast one inflatable support which support or supports have oppositesides which are internally reinforced and are at least partially filledwith a settable material to form a rigid structure when the material isset, the internal reinforcement holding together the sides prior to thesetting of the material.

The invention extends to a method, an inflatable support, inflatablesupport member, formwork or a structure wherein, warning notices orsigns or other indicia are pre-printed on the outside of the or eachcontainer, blast protection structure, inflatable support, inflatablesupport member or formwork.

The invention extends to a method, an inflatable support, inflatablesupport member, formwork or structure substantially as described andillustrated herein.

Also envisaged is a method of erecting a rigid blast protectionstructure including the steps of filling or partially filling at leastone container having internal reinforcement, such as drop stitchmaterial, with a settable semi-liquid cement which is thereafter allowedto set to form a free-standing rigid structure.

Conveniently, the method also includes the steps of forming at least twospaced apart rigid wall members in accordance with the aforesaid methodand thereafter providing a gas-fillable roof member spanning the atleast two wall members, the roof member being of drop stitch material,and thereafter forming a second roof member from a settable cement andfollowing setting of the second roof member deflating the first roofmember such that the second roof member then becomes a structural roofmember between the at least two wall members.

In accordance with a refinement to this concept a third, larger, roofmember is then formed over the second, set, roof member after the firstroof member has been deflated, to thereby provide increased structuralstrength.

In a further refinement to the method of the invention the blastprotection structure is formed sequentially, particularly where itsfinal height is too high for the formwork to be provided solely by dropstitch material. Thus, a relatively high barrier may be provided havinga generally “A” shaped cross-section made up of one or severalinflatable containers which are then inflated with air or water,whereafter the lowermost one or portion thereof is filled with liquidcement and/or cement/sand or other particulate which is then allowed toset, whereafter the next successive layer is formed, supported by thefirst such layer and also by the drop stitch material. In this way, ablast protection structure such as a wall 3 m high can be constructed ine.g. three separate stages without the use of construction equipmenttypically found on a building site but usually not available in e.g.battlefield conditions.

Conveniently, anchor points may be provided between the second and/orthird roof members and each wall member, and each wall member may itselfbe anchored to existing structures by e.g. reinforcing rods sealinglyinserted through the bags prior to the cement setting. Additionally oralternatively, the insides of the bags may include reinforcement in theform of rods, which may be steel or e.g. composite plastics material,such that when the structure is complete it is effectively a reinforcedconcrete structure.

Utilising the concept of the invention in which the drop stitchcontainers are used as formwork, retaining their general shape whilstcement sets, it is therefore possible to erect permanent rigidstructures quickly and effectively with only inflatable equipment and/orpourable material and without separate rigid formwork being required orseparate equipment for lifting such being necessary.

In accordance with a yet another aspect of the invention there isprovided an inflatable support member adapted to, in use, bridge the gapbetween adjacent support members and permit a second support member tobe formed and set thereon, such as a concrete lintel, whereafter thefirst support member is adapted to be deflated to allow the secondsupport lintel to thereafter bridge the gap between the two wallmembers. The inflatable support member may conveniently be made of dropstitch fabric.

In a refinement to the concepts of the first and second aspects of theinvention, internal reinforcement is provided for the drop stitchcontainers, either integrally with the containers prior to them beinginflated, or by them being adapted to be externally accessible toreinforcement following inflation and prior to any cement settingtherewithin.

In accordance with yet another aspect of the invention, there isprovided inflatable formwork shaped to form a rigid structural memberwhen the material, such as concrete, of which the rigid structuralmember is to be formed sets. Conveniently, a set of such inflatableformwork may be provided for e.g. forming individual structural membersfor subsequent assembly into a building, such as wall members, floormembers, roof members, lintels and so on.

In a further refinement to the invention, warning notices or signs orother useful information may be pre-printed on the outside of thecontainers to thereby provide temporary, semi-permanent or permanentinformation as the case may be.

The invention will now be described, by way of example only, withreference to the accompanying drawings, in which:

FIG. 1 is a perspective view of a rigid blast protection structure madein accordance with the method of the invention;

FIGS. 2 & 3 show roof members suitable for the structure illustrated inFIG. 1;

FIG. 4 illustrates a filling means;

FIG. 5 shows internal reinforcement;

FIG. 6 shows an anchor suitable for anchoring a structure to a building;and

FIG. 7 shows a blast protection structure.

Referring firstly to FIG. 1 there is shown a perspective view of a rigidblast protection structure in the form of a rectangular sarcophagus 1made up of interconnecting walled containers of drop-stitch materialfilled with set cement to thereby form a blast protection structurewhich may be used as e.g. a foxhole in combat or it may be used as awater reservoir if provided with a suitable base, or it may be filledwith sand to act as a repository for an exploded ordnance, or it mayprotect a pre-existing installation or even stored ordnance from theeffects of bullets and bombs etc.

Although the shape of the structure 1 is relatively simple in shape itwould ordinarily require during construction shuttering on the insideand outside with attendant reinforcements for such shuttering whereaftercement would be poured into the void therebetween and allowed to setbefore the shuttering is removed, therefore being unsuitable forbattlefield conditions for a variety of reasons, not least the timeinvolved and the amount of equipment and skill necessary for thesestructures construction.

In contrast, through the use of drop-stitch material making up theinterconnected containers 2, 3, 4 and 5, such a structure can be easilyand quickly inflated to the required shape, by air and/or water by theuse of a pressure relief valve (not shown) or, if too tall to bear itsown weight, despite being made of drop-stitch material, it may be onlypartially filled with water with cement being added later or apre-mixture of a settable semi-liquid cement may be used initially andfilling of the containers stops when the limit of self-support isreached, whereafter the cement is allowed to set and the processrecommenced until the entire structure is complete.

The foregoing concept can be used to construct buildings or similarstructures having roofs made of cement materials as such concrete, evenreinforced concrete, without the use of specialist equipment, includinglifting equipment such as cranes etc. This is shown with reference toFIGS. 2 and 3, which respectively show initial and final phases ofconstruction of a roofed structure. In FIG. 2 sidewalls 6, 7 have beenerected, filled with cement either in a single operation or in asequential operation as described with reference to the structure ofFIG. 1, and the cement has been allowed to set. Thereafter, threeinflatable ceiling container 8, 9 and 10 are inflated with air underpressure, the central ceiling container being supported in its requiredposition by e.g. a pair of adjustable props although other supportscould be used including even an air cushion, and the side containers 8,9 simply rest for their most part on the tops of the wall structure 6and 7 such that the containers 8, 9, 10 thereafter provide a generallyplanar roof capable of supporting a lintel-shaped container 11 which maythereafter be filled with e.g. liquefied cement which is then allowed toset. When the lintel 11 sets then the containers 8, 9 and 10 can simplybe deflated, with the centrally disposed container 9 then being removedentirely and containers 8, 10 simply resting in place underneath thelintel 11.

As can be seen by reference to FIG. 3, the presence of a concrete lintel11 above the concrete walls 6,7 thereafter provides a larger container12, to be placed over the lintel 11, filled with liquefied cement andthen allowed to set. The container 12 may itself be a larger lintel orit may be more planar form extending over several lintels 11 which,along with the tops of the sidewalls 6, 7 collectively support theplanar container 12 until it is set, thereafter forming a routeprotective structure with, effectively, tools which are mostlyinflatable.

In FIG. 4 there is shown a schematic arrangement suitable for ensuringthat liquid cement or other settable material is evenly distributedthroughout the entire container 13. This is achieved by the use of aninbuilt inlet tube 14 having a closed end 15 at the opposite end of thecontainer 13 and a closable inlet end 16. Outlet orifices 7 are arrangedradially and linearly along the tube 14 within the confines of thecontainer 13 such that when the tube 14 is being filled with liquidcement, the cement can be evenly dispersed throughout the interior ofthe container 13. As a refinement to this, reinforcement in the form ofsteel rods or strips of Kevlar may be inserted into the tube before itsets so that the finished structure is reinforced.

FIG. 5 shows a prearranged reinforcement concept where the container 18includes a series of spaced reinforcing members 19, which may be steelor where weight is a consideration a flexible material, such that afterthe container 18 is inflated to the condition as shown the reinforcingmembers 19 are spaced apart with respect to each other within thecontainer 18, which may thereafter be filled with liquid cement to forma reinforced concrete structure.

In FIG. 6 there is shown a tie rod concept where the container 13 ofFIG. 4 is shown tied to e.g. the side of a building 20 by the expedienceof extending the inner tube 14 into an aperture 21, which may be apre-existing aperture or purpose formed, and thereafter driving a pin 22through the inlet tube 14 before the cement is allowed to set,thereafter tying the container 13 to the building 20.

In FIG. 7 the concept is taken further to the stage whereby thecontainer 23 has built in openings in the form of a door aperture 24 andpill box style window slits 25 which collectively remain open when thecontainer 22 has been filled with liquid cement and the cement has thenset.

In FIG. 8 is shown a further concept whereby a container 26 is intendedto act as reinforced building block with built in reinforcement rods 27extending through, in this case, two of the outer walls of the container26 intended to be received within correspondingly shaped recesses 28within another container 27 adjacent thereto. With this arrangement, onecontainer 26 may be inflated and formed into a rigid block, whereafteranother container 26 may be placed adjacent thereto, inflated such thatthe reinforcement rods 27 may be inserted into correspondingly shapedrecesses 28 as appropriate, whereafter the second such container 26 isfilled with cement which is thereafter allowed to set.

The realisation that drop stitch material can be used to replace rigidformwork therefore allows for a variety of structures to be easilyerected which, when set, can therefore be regarded as permanentstructures which can provide valuable protection to personnel andproperty at locations where heavy construction equipment is unavailable.In particular the invention is suited for use in battlefield conditionswhere there is a general need to ensure that such structures can beerected quickly and effectively, especially if the settable semi liquidcement includes an accelerating agent allowing for such rigid structuresto be formed quickly. In addition, such structures may be formed underwater to protect e.g. pipelines, which can be easily and quicklyprotected on a permanent or semi permanent basis.

In accordance a third aspect of the invention as shown with reference toFIG. 9 the container 29 may include on one side thereof a ground sheet30 intended to cover the whole of the container on that side and aseparately inflatable inner container 31, the containers 29 and 31defining the shape of a structural member, in this case a rectangularframe, which may then be formed therebetween by the use of settableconcrete, which is thereafter allowed to set, whereafter the containers29, 31 are deflated and the concrete frame thereafter removed, foranother such frame to be then made by the same method. In this way, aset of such containers may be provided for making e.g. lintels, panelsfor forming walls and roofs, and so on. It will be appreciated that inthis embodiment of the invention it may be utilised in othercircumstances, such as where conventional formwork is not readilyavailable but where rigid structures are required, such as in aridclimates or mountainous regions above the tree line.

Whilst planar surfaced structures have been illustrated it will beunderstood that it is possible to produce non-planar, eg simple,compound, concave or convex curves using the equipment and techniquesdescribed. Whilst cement based materials have been described above itwill be apparent that other materials may be used instead e.gparticulates like sand or aggregate, which may be pumped in liquidsuspension and allowed to settle when the transporting liquid isdrained. Alternatively a foam material may be used which could containparticulates. A polymeric material could be used also which could befoamed and/or have particulates mixed with it. Blast protectionstructures have been described and illustrated above however, theconstruction of other structures may be carried out with according tothis invention.

1. A method of erecting a structure including the steps of: filling orpartially filling at least one container having internal reinforcementwith a settable material which is thereafter allowed to set to form afree-standing rigid structure.
 2. A method of erecting a structure asclaimed in claim 1 further including the steps of forming at least twospaced apart rigid structures, to form at least two wall members andthereafter providing a fluid-fillable roof member spanning the at leasttwo wall members, the roof member having internal reinforcement, andthereafter forming a second roof member from the settable material andfollowing setting of the second roof member, deflating the first roofmember such that the second roof member then becomes a structural roofmember spanning the at least two wall members.
 3. A method of erecting astructure as claimed in claim 2 further including the steps of forming athird roof member over the said structural roof member after the firstroof member has been deflated, to thereby provide increased structuralstrength.
 4. A method of erecting a structure as claimed in claim 3wherein the the third roof member is formed by filling at least onefurther container with a settable material which is thereafter allowedto set.
 5. A method of erecting a structure as claimed in claim 3wherein anchor points are provided between the second, structural, roofmember and/or third roof members and each wall member.
 6. A method oferecting a structure as claimed in claim 2 wherein at least one of thesaid wall members is anchored to an existing structure.
 7. A method oferecting a structure as claimed in claim 1 wherein the inside of the atleast one container is filled or partially filled with the settablematerial and includes further reinforcement in the form of one or morerods.
 8. A method of erecting a structure as claimed in claim 1 whereinthe said at least one container is filled sequentially such that atleast one settable material filling is allowed to set before another isintroduced.
 9. A method of erecting a structure as claimed in claim 1wherein the or each container is used as formwork so that the method canbe performed employing only inflating equipment and/or means for pouringthe settable material and without separate rigid formwork or liftingequipment
 10. A method of producing a structure having one or moreinflatable containers each having internal reinforcement, including thesteps of inflating the or each container with a fluid, whereafter thelowermost one or portion thereof is filled with a settable or pourablematerial which is then allowed to set or settle, whereafter the nextsuccessive layer is formed, supported by the first such layer and alsoby the internal reinforcement.
 11. A method of erecting or producing astructure as claimed in claim 10 wherein the internal reinforcement isin the form of dropstitch material.
 12. A method of erecting orproducing a structure as claimed in claim 10 wherein the settable orpourable material is: a settable cement or gypsum based material; aparticulate material such as sand or aggregate which may settle to formto a substantially rigid mass; or a settable foam and/or polymericmaterial.
 13. An inflatable support member adapted to, in use, bridgethe gap between adjacent underlying support members and to permit asecond support member to be formed and set thereon, such as a concretelintel, the inflatable support member being adapted to be subsequentlydeflated to allow the second, set, support member to thereafter bridgethe gap between the two adjacent underlying support members.
 14. Aninflatable support member as claimed in claim 13 wherein the member ismade of dropstitch fabric to provide internal reinforcement.
 15. Aninflatable support member as claimed in claim 13 wherein furtherreinforcement is provided in the form of reinforcing rods.
 16. A methodas claimed in claim 6 wherein the further internal reinforcement isprovided for the or each container or support either integrally with theor each container/support prior to the or each container/support beingfilled, or by the or each container/support being adapted to beexternally accessible for allowing the introduction of the herreinforcement following filling and prior to any material setting in oron the container/support.
 17. Inflatable formwork fillable with asettable or pourable material and shaped to form a rigid structuralmember, when the material of which the rigid structural member is to beformed sets, the formwork having internal reinforcement.
 18. A set ofinflatable formwork as claimed in claim 17 for forming individualstructural members for subsequent assembly into a structure. 19.Inflatable formwork or a set of inflatable formwork as claimed in claim18 wherein the internal reinforcement is drop stitch material.
 20. Ablast protection structure formed from at least one inflatable supportwhich support or supports have opposite sides which are internallyreinforced and are at least partially filled with a setiable material toform a rigid structure when the material is set, the internalreinforcement holding together the sides prior to the setting of thematerial. 21-22. (canceled)
 23. A method as claimed in claim 15 whereinthe further internal reinforcement is provided for the or each containeror support either integrally with the or each container/support prior tothe or each container/support being filled, or by the or eachcontainer/support being adapted to be externally accessible for allowingthe introduction of the further reinforcement following filling andprior to any material setting in or on the container/support.